Application of the hottest GPRS in distribution ne

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Application of GPRS in distribution monitoring

Abstract: distribution transformer is an important equipment in distribution. Distribution transformer is the most basic unit of power supply. The monitoring of distribution transformer is of great significance to distribution automation management, line loss analysis, load forecasting and power demand side management. GPRS will be widely promoted and applied in distribution transformer monitoring

0 introduction

with the gradual improvement of power city and rural reconstruction, the completion of one meter per household project and meter reading to each household has put forward new requirements for reducing line loss, improving power supply quality and ensuring the reliability and security of power supply. In addition, due to the power industry system reform and power shortage in the system in the past two years, simple electric energy measurement can no longer meet the monitoring and management needs of distribution transformers. At the same time, new requirements are put forward for the real-time measurement and control management of the operation status of distribution transformers. It is required to realize intelligent management of power consumption marketing management and power demand side management (DSM). It is required to conduct intelligent monitoring on the low-voltage side of distribution transformer, master the accurate data of distribution transformer operation, and conduct reasonable management according to the demand, so as to improve the power supply quality

1 distribution transformer (distribution transformer)

distribution transformer (hereinafter referred to as distribution transformer) is the equipment that directly distributes electric energy to low-voltage users in distribution, and is the dividing point between low-voltage (10kV) distribution and 380/220v distribution of users. The distribution transformer is installed in the pole, distribution room and box type substation. It has the characteristics of dispersion, changeable geographical environment, wide coverage, numerous users, and is vulnerable to the impact of user capacity increase and urban construction

2 function of real-time monitoring of distribution transformer operation

through the real-time monitoring of distribution transformer, the operation of distribution transformer can be grasped in time to prevent the equipment from burning due to serious overload of distribution transformer load, and the serious imbalance of three-phase load, resulting in the accelerated damage of graphene pilot production line established by the company at present, the uneconomical operation state caused by long-term light load operation of distribution transformer and the low power factor caused by a large number of inductive load operation High line loss, etc

real time monitoring, reading, analysis, processing and control of distribution transformer operation can timely adjust the operation status of distribution transformer, reasonably configure the capacity of distribution transformer, adjust the low-voltage intelligent reactive power compensation control of distribution transformer, and ensure the safe, stable and efficient operation of distribution transformer

perfect, scientific and accurate real-time monitoring of distribution transformer, provide reliable operation data and historical data for distribution automation management, effectively reduce line loss, and provide accurate data for load forecasting, line loss analysis, and power demand side management (DSM); Accurately crack down on power theft, load forecasting guidance for capacity expansion and installation, etc; To provide scientific data for the analysis of power consumption, power consumption nature and the growth trend of power load, and for the planning work such as system capacity increase and distribution transformer distribution point selection; At the same time, improve work efficiency, reduce labor costs, and scientifically improve the automation level of distribution management

3 distribution transformer operation real-time monitoring communication group

3.1 problems of distribution transformer operation real-time monitoring communication group; The geographical and topographical distribution is unbalanced and scattered. Based on the above characteristics, optical fiber communication, wired cable and power carrier communication group are not feasible in terms of technology or capital input-output ratio. The communication group for real-time monitoring of distribution transformer has been perplexing the promotion and implementation of real-time monitoring of distribution transformer

3.2 communication requirements for real-time monitoring of distribution transformer operation

the amount of data monitored by distribution transformer is large, and the real-time requirements are not too high. The monitoring terminal has the storage function, so it is not necessary for each distribution transformer monitoring terminal to occupy a channel to communicate with the distribution transformer management master station at the same time

it is required to have the function of point selection call test communication, and the distribution transformer management administrator can call test the real-time data of the distribution transformer monitoring terminal at any time

for special out of limit alarm signals affecting the operation of distribution transformer, the distribution transformer monitoring terminal shall upload them to the distribution transformer management master station in time

the construction, installation and maintenance of master station and terminal are convenient and the operation cost is low

it is better to provide transparent transmission channel or be compatible with a variety of communication protocols

3.3 current communication group scheme

at present, there are three communication schemes that are more suitable for the requirements and characteristics of real-time monitoring communication of distribution transformer:

⑴ public exchange scheme

⑵ radio data transmission station scheme

⑶ GPRS scheme

two schemes (1) and (3) belong to the public scheme, and (2) belong to the private scheme built by the user

3.3.1 public switching scheme

public switching applications are quite popular. Some people work to solve the problem: there is a public switching with the place where they live. Public switching can be used not only for calls but also for data transmission. However, the disadvantages of the public switching scheme are:

① it is necessary to set up a private line and pay the installation fee, monthly rental fee and use fee to the telecom company

② for non transparent data transmission, a certain time limit is required for modem from dial-up call to connection

3.3.2 scheme of wireless data transmission radio station

wireless data transmission radio station is applicable to the data monitoring of scattered communication points, and is just applicable to the monitoring of distribution transformer. It has a special data transmission frequency band, and the working frequency is 220mhz ~ 240mh. In addition, there are some workpieces on the transmission. The disadvantages of the wireless data transmission radio scheme are as follows:

① the initial opening needs to pay a certain fee to the local radio management committee, and then pay a certain frequency occupation fee every year, which is high

② there are certain restrictions on the communication distance (the farthest distance in the plain is 50km), and it is greatly affected by buildings and mountains

③ professional personnel are required for maintenance and management, and the construction and maintenance costs are very high

3.3.3 GPRS scheme

based on the characteristics of the above distribution transformer and the shortcomings of the above two communication group modes, the proposal of GPRS data communication scheme solves a series of problems, and scientifically and effectively solves the communication group problem of real-time measurement and control of distribution transformer

gprs is a packet switched data bearer and transmission network developed on the basis of GSM. It adopts advanced wireless packet technology and can provide rich wireless access means for industries such as water conservancy, power, transportation and banking. The mobile gprs scheme has the following advantages:

① transparent two-way data transmission and automatic link maintenance

② only need to open a SIM card with the mobile company, and the fee can be used in a monthly manner, with low operation cost

③ forever. Once GPRS is activated, it will always be maintained. There is no problem of dropping the line. It will only be charged when traffic is generated

④ fast login, new grouping service, no need for long-time dial-up connection process

⑤ relevant technicians should also carefully inspect whether the working state of the relevant parts of the equipment conforms to the normal standard high-speed transmission, and the maximum theoretical GPRS transmission speed is 171.2

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